Weight Limit Roof Ladder

[pddgm]

I have seen rigs with a lot of stuff hanging off the roof ladder going down the road and wonder if there is a way to determine how much the will support.?

We have two bicycle's one a regular mountain type and the other an adult trike, I plan on taking the rear wheels off the trike and hang it by the rear axle on a hanger made with steel bar and padded with foam rubber. I figure the mountain bike weights maybe 30 lbs and the trike without the rear wheels about 50 maybe. I plan on strapping them down tight so they won't bounce. Any thoughts as if the ladder will handle it or ?


Joe

[Steve Ownby]

Originally Posted by pddgm

I have seen rigs with a lot of stuff hanging off the roof ladder going down the road and wonder if there is a way to determine how much the will support.? We have two bicycle's one a regular mountain type and the other an adult trike, I plan on taking the rear wheels off the trike and hang it by the rear axle on a hanger made with steel bar and padded with foam rubber. I figure the mountain bike weights maybe 30 lbs and the trike without the rear wheels about 50 maybe. I plan on strapping them down tight so they won't bounce. Any thoughts as if the ladder will handle it or ? Joe

I think they are all designed for an adult male to climb to the roof. Most motorhome manufacturers say 225-250 pounds for a man on the roof. I would try to limit bounce as much as possible.

[jeffwit]

I weigh about 230. The ladder supports me well when I climb up and down it. But I haven't ridden on it while we're going down the road…

[TXiceman]

The problem is not the static weight on the ladder. The dynamic loading comes from the rear of the motorhome going up and down. The dynamic load can be many times the static loading. So a 50# static load can easily exert loads of 200# plus. A cyclic load can cause fatigue of the ladder or mounts.

Check the bikes often.

Ken

[Steve N Sal]

I weigh in at 225 and our ladder handles me just fine. I had the idea of carrying my bike on the ladder but after putting it on there I just decided againtst it. I didn't care for the waynthe bike hungbon the rack. I just purchased a rear hitch rack for our pt Cruiser and carry it back there. Just me I guess but I feel better about it.

[gruelens]

I tip the scales at 1/8th of a ton (do the math.) A few screws holding my ladder did not have a good bite in the fiberglass end cap. I changed all the screws out to a larger size. The ladder is much more solid now. May help you if you are storing items on the ladder while traveling.

[TdogKing]

I chose not to trust the coach ladder anymore before something happened. I bought a telescoping ladder that I put right next to the coach ladder so I can use one hand to ensure it won't move side to side. I feel much safer going up now.

[H. Miller]

Our Monaco has a "sticker" on top that limits weight on the ladder to 300 lbs. while in motion.

[John S.]

They are rated usually at 250 pounds. The attachments will start to rust and weaken over time too. I was talking to a paint and graphics and collision shop tat only does RVs and he showed me a couple old ones. They were scary to look at after ten years. I use a fold up ladder now.

[JFXG]

As a rule of thumb, a typical ladder has approx. eight attach points, so if each point holds only 30 lbs you've got a 240 lb limit. However, as to your question-- what TXiceman referred to as the dynamic load is your primary issue. Its all about the G-loading. Ordinary civilian aircraft are designed to tolerate positive G loads in the +2.5G to +3.8G range, so I figure well below that range is a good limit. Perhaps 1.5G.


So, if the general consensus is that the ladders can support 250lbs, I wouldn't hang any more than about 100lbs on it, allowing for about 1.5G from a bad bounce on the road, plus a good safety factor.


I've been carrying a 40lb folding ladder on mine for two years with no ill effects. I think your bikes will be fine.


Good Luck!

[336muffin]

Originally Posted by TXiceman

The problem is not the static weight on the ladder. The dynamic loading comes from the rear of the motorhome going up and down. The dynamic load can be many times the static loading. So a 50# static load can easily exert loads of 200# plus. A cyclic load can cause fatigue of the ladder or mounts.

Check the bikes often.

Ken

I fully agree! Would you ride the ladder while on a bad stretch of highway?

[Dutch Star Don]

I think Ken (TXiceman) has the right answer. It's not what your ladder is rated for. Most of them will work for anyone from 250 -300 pounds. It's the load of those bicycles, even secured tightly, getting bounced around on the ladder joints as you go down the road.

Since it's a Pace Arrow, is there a support you can fabricate from the last rung of the ladder to the rear bumper. Something that quick connects. This would take the load off of the ladder while underway.

[wa8yxm]

Originally Posted by Steve Ownby

I think they are all designed for an adult male to climb to the roof. Most motorhome manufacturers say 225-250 pounds for a man on the roof. I would try to limit bounce as much as possible.

I would say a juvinille male, at 300 pounds the ladder held me OK, but the ladder mounts came right off the motor home.

My new ladder holds me fine, but not while it's mounted to the motor home. (Replaced the ladder with a pair of hooks and hang a convertable, Extension/step, ladder on the hooks.. Each hook can easily hold my 300 pounds.. Yes, they are overbuilt. )

[JFXG]

Originally Posted by TXiceman

.......The dynamic load can be many times the static loading. So a 50# static load can easily exert loads of 200# plus.....

Ken, do you really think you'd see 4G+ on a motorhome? I'm not being facetious- I'm asking. I would wonder about the tires....